An exacerbation of chronic obstructive pulmonary disease (COPD) of sufﬁcient severity
to necessitate hospital admission indicates a poor prognosis, carrying a 6-26 per cent
mortality.1-3 An 11 per cent increase in hospital mortality has been reported, increasing
over the next two months, six months and two years of follow-up to 20 per cent, 33 per
cent and 49 per cent, respectively.2 Another study found ﬁve-year survival rates of 45 per
cent after hospital discharge, which decreased to 28 per cent with any further episode of
hospitalization.4 The outcome of invasive mechanical ventilation (IMV) in patients with
COPD is disappointing, with reported survivals of between 20 and 50 per cent.5